Defensive publication

ABSTRACT

METHOD OF QUANTITATIVELY DETERMINING THE PRESENCE OF PHENOLIC COMPOUNDS HAVING AN OPEN PARA-RING POSITION BY CONTACTING THEM WITH 2.6-DIBROMOQUINONE CHLORIMIDE AT A PH OF FROM 8.5 TO 10.5 TO FORM A DIBROMOINDOPHENOL DYE. IN THE KNOWN PROCESS, THE DYE IS ANALYZED COLORIMETRICALLY TO DETERMINE THE CONCENTRATION OF THE PHENOLIC IN THE SOLUTION. THE IMPROVEMENT COMPRISES CONTACTING THE REACTANTS AT A TEMPERATURE WITHIN THE RANGE FROM 45* TO 50* CONTROLLED TO +0.5* C. BY CARRYING OUT THE REACTION WITHIN THIS TEMPERATURE RANGE, THE FORMATION OF THE DIBROMOINDOPHENOL DYE TAKES PLACE IN LESS THAN 1 HOUR AS COMPARED TO A REACTION TIME OF AS HIGH AS 24 HOURS AT ROOM TEMPERATURE. REACTION TIMES AS SHORT AS 15 MINUTES ARE POSSIBLE AT TEMPERATURES WITHIN THE RANGE OF 50+0.1&#34;C.

DEFENSlV PUBLlCATlON UNITED STATES PATENT OFFICE Published at the request of the applicant or owner in accordance with the Notice of Dec. 16, 1969, 869 O.G. 687. The abstracts of Defensive Publication applications are identified by distinctly numbered series and are arranged chronologically. The heading of each abstract indicates the number of pages of specification, including claims and sheets of drawings contained in the application as originally filed. The files of these applications are available to the public for inspection and reproduction may be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to the merits of alleged invention. The Patent Office makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED SEPTEMBER 21, 1971 T890 001 PROCESS FOR THE QUAP JTITATIVE DETERMINA- TION OF THE PRESENCE OF PHENOLICS Charles Eugene Hamilton, Midland, Mich., assignor to The Dow Chemical Company, Midland, Mich. Filed Sept. 19, 1969, Ser. No. 859,573 Int. Cl. G01n 33/18 US. Cl. 23-230R No Drawing. 5 Pages Specification Method of quantitatively determining the presence of phenolic compounds having an open para-ring position by contacting them with 2,6-dibromoquinone chlorimide at a pH of from 8.5 to 10.5 to form a dibromoindophenol dye. In the known process, the dye is analyzed colorimetrically to determine the concentration of the phenolic in the solution. The improvement comprises contacting the reactants at a temperature Within the range from 45 to 50 controlled to :05" C. By carrying out the reaction Within this temperature range, the formation of the dibromoindophenol dye takes place in less than 1 hour as compared to a reaction time of as high as 24 hours at room temperature. Reaction times as short as 15 minutes are possible at temperatures Within the range of 50:0.1 C. 

